Li Junhao, Xu Xuefeng
School of Technology, Beijing Forestry University, Beijing 100083, China.
Materials (Basel). 2025 May 16;18(10):2327. doi: 10.3390/ma18102327.
In this study, a contact-separation triboelectric catalytic device was designed and constructed to systematically investigate the underlying degradation mechanism. The device enabled precise control of the contact-separation process between frictional surfaces. Polytetrafluoroethylene (PTFE) and polyethylene terephthalate (PET) films were selected as the triboelectric pair, and methylene blue (MB) was used as the model organic pollutant. Experimental results demonstrated that the contact-separation process in an aqueous environment effectively promotes the degradation of organic dyes. For an MB solution with an initial concentration of 5 mg/L, a degradation efficiency of 40.34% was achieved within 3 h. Moreover, the device exhibited excellent repeatability and stability, with no significant decline in performance after 15 h of continuous operation. Control experiments confirmed that the degradation originates specifically from the contact-separation interaction between the PTFE and PET surfaces. Free radical quenching experiments identified superoxide radicals (·O) and hydroxyl radicals (·OH) as the primary reactive species responsible for degradation. Based on these findings, a microscopic mechanism is proposed: during contact, triboelectric charging generates electrons (e) and holes (h) on the surfaces; upon separation, these charges interact with the solution-e reduce dissolved oxygen to form ·O, while h oxidize hydroxide ions (OH) to produce ·OH. The combined action of ·O and ·OH ultimately results in the efficient degradation of MB.
在本研究中，设计并构建了一种接触-分离摩擦电催化装置，以系统地研究潜在的降解机制。该装置能够精确控制摩擦表面之间的接触-分离过程。选择聚四氟乙烯（PTFE）和聚对苯二甲酸乙二酯（PET）薄膜作为摩擦电对，并使用亚甲基蓝（MB）作为模型有机污染物。实验结果表明，在水环境中的接触-分离过程有效地促进了有机染料的降解。对于初始浓度为5 mg/L的MB溶液，在3小时内实现了40.34%的降解效率。此外，该装置表现出优异的重复性和稳定性，连续运行15小时后性能无明显下降。对照实验证实，降解具体源于PTFE和PET表面之间的接触-分离相互作用。自由基猝灭实验确定超氧自由基（·O）和羟基自由基（·OH）是负责降解的主要活性物种。基于这些发现，提出了一种微观机制：在接触过程中，摩擦起电在表面产生电子（e）和空穴（h）；分离时，这些电荷与溶液相互作用——e将溶解氧还原形成·O，而h将氢氧根离子（OH）氧化产生·OH。·O和·OH的共同作用最终导致MB的有效降解。
